富油甲烷燃燒環境下壓力對NO生成的影響

Pressure Effect on NO Formation in Fuel-Rich Combustion of Methane

袁曉峰(Tony Yuan) ； 賴祐炫(Y.S. Lai)

《中國航空太空學會學刊》 34卷4期 (2002/12) Pp. 379-385

https://doi.org/10.6124/TAASRC.200212_34(4).11

摘要

本研究使用甲烷／空氣的燃燒反應機構(Reaction Mechanism)配合CHEMKIN的火燄模擬程式來探討不同壓力下(1~3 atm) NO的生成路徑。經過NO-LIF的實驗驗證，本文所採用的反應機構，可預測1~3 atm當量比0.8~1.3之甲烷／空氣預混火焰中NO的濃度，尤其在富油環境下，此反應機構的誤差約爲20%。利用此反應機構來探討富油環境下(φ=1.2) NO的生成路徑，顯示在1~3 atm，1800 K時Thermal NO佔NO總生成量的一半以上(61%@1atm, 59%@3atm)。在一大氣壓1500K時，Thermal NO的比例會減少(61%@1800K, 45%@1500K)，Prompt NO的比例保持不變(29%@1800K, 30%@1500K)，NNH反應機構所生成的NO的比例會增加(11%@1800K, 20%@1500K)。壓力的增加則會使N→H2CN→HCN→…→NO(3%@1atm, 11%@3atm)、N2→CN→NCO→…NO(37%@1atm, 48%@3atm)的反應路徑變得更重要。

關鍵字

NO ； 反應動力 ； 富油燃燒

並列摘要

A methane/air reaction mechanism is used to investigate NO formation at different pressures (1~3atm) and equivalent ratios (0.8~1.3). The NO concentration is evaluated by CHEMKIN premixed flame code and verified by NO-LIP experiment measurement. The results show the mechanism predicts reasonable NO formation at pressure of 1~3 atm in fuel rich conditions (17% overestimated at 1 atm and 20% underestimated at 3 atm). From NO formation analysis in fuel rich conditions, the major contribution of NO is from thermal NO at 1800K (61%) and decreases with temperatures (45% at 1500K). The weighting of prompt NO in total NO formation is almost unchanged in different temperature. The importance of NNH mechanism is more significant at lower temperature (11% at 1800K, 20% at 1500K). Pressure has minor effect on the weighting of the different sources of NO formation. However, increasing of pressure increases the importance of N→H2CN→HCN→…→NO (3% at 1 atm, 11% at 3 atm) and N2→CN→NCO→…NO (37% at 1 atm, 48% at 3 atm) formation pathways.

並列關鍵字

NO ； kinetic ； fuel rich combustion